May is in the books, and a lot of teams and players took gigantic steps forward. Unfortunately, some players and teams also took massive steps backward. Here’s a recap of the month.

AL Hitter of the Month: Edwin Encarnacion. 16 homers in May for Encarnacion powered the him to a .281/.369/.763 line, and pushed the Blue Jays to a major league best 21-9 record over the month of May. His OPS rose from .747 at the end of April to .948 at the end of May. Typically, this award goes to a player who had much a much better batting average and on-base percentage than Encarnacion, but his absurd power display cannot be ignored.

AL Worst Hitter of the Month: Alejandro de Aza. After a pair of great seasons with the White Sox, de Aza has fallen off a cliff this year. In May, Chicago’s left fielder hit just .161/.237/.195. A BABIP for the season that’s more than 100 points below his career average does a lot to explain his struggles, but with Adam Eaton playing reasonably well and Dayan Viciedo finally tapping into his potential, de Aza’s rough year and ever-increasing salary could lead to him being nontendered after the season – or maybe even traded in July.

NL Hitter of the Month: Yasiel Puig. Puig has answered every one of his critics with his performance so far this year, and he’s a close second to Troy Tulowitzki in the NL MVP race at the one-third mark of this season. Puig hit .398/.492/.731 with eight homers and four stolen bases in May, and has a nice shot at having a 30/30 season this year. The guy is doing it all – his slash lines are better across the board, he’s hitting for much more power, he’s walking more, he’s striking out less, and he seems to be less of a headache in the outfield and on the basepaths. Oh, and he’s only 23-years old.

NL Worst Hitter of the Month: Danny Espinosa. Remember when Danny Espinosa had a good spring and a good April, and many pundits claimed that 2013 was just a blip on the radar, and that he was back and as good as ever? Well, in May, Espinosa undid all of that goodwill (not that anyone noticed) after he hit just .125/.195/.263 and struck out 37 times in 87 plate appearances. It’s admittedly a small sample, but Espinosa hasn’t shown that any part of his game is back in gear, aside from his power.

AL Pitcher of the Month: Corey Kluber. Who in the hell is Corey Kluber? You can’t call Kluber a fluke anymore after he followed up his solid April with a terrific May. For the year, he’s always surpassed his fWAR total from 2013 in 67 fewer innings, and he leads all of baseball in both fWAR and strikeouts. In May, the 28-year old pitched to a 2.09 ERA while striking out 60 and walking just eight in 43 innings.. Kluber is the biggest reason why the disappointing Indians haven’t been completely buried in the AL Central quite yet.

AL Worst Pitcher of the Month: Brandon Maurer. It’s funny. We all got on the Mariners for not doing more to bolster their offseason acquisition of Robinson Cano, specifically in the rotation. Maurer was awful last year, and they rolled him out again this year to similar results. Before being demoted to AAA on Friday, Maurer started five games in the majors in May and pitched to a 7.77 ERA while walking 11 and striking out just ten in 24 1/3 innings. Somehow, the Mariners won one of those five starts. The more you know, I guess.

NL Pitcher of the Month: Jeff Samardzija. The man they call Shark finally won a game in May after failing in every one of his attempts this season, and not a moment too soon – he got slaughtered in his first start of June. At any rate, Samardzija was better in May than he was in April, posting a 1.32 ERA in 34 innings to go along with 33 strikeouts and eight walks. We can go ahead and kill that meme of “Samardzija will be the first winless player to win the Cy Young!”, but it’s definitely possible that he could have a year like Nolan Ryan did in 1987, when he led the National League in ERA and strikeouts, but finished fifth in the Cy Young voting because he was just 8-16.

NL Worst Pitcher of the Month: Franklin Morales. Colorado had the worst record in the NL West in May, and you can place some of the blame for that at the feet of Morales. He’s not expected to be the ace of the Rockies staff, but he still needs to do better than his 20 strikeouts, 14 walks, and 7.54 ERA in May over the rest of the season. In an odd note, Morales is getting absolutely lit up away from Coors Field this year (.293/.374/.558), but is keeping his head above water at home.

AL Rookie of the Month: George Springer. I really wanted to give the nod to Xander Bogaerts here, because he’s flipped the switch in May after the Red Sox re-signed Stephen Drew earlier in the month. But Springer’s been too damn good in his first full month in the majors. His power has showed up, delivering ten homers in 26 May games. All that power has led to a .294/.385/.647 line for the month, and a .259/.344/.500 line for the season. Yeah, there are still some flaws with Springer’s game (too many strikeouts, most notably), but he put a stamp on his season this month.

NL Rookie of the Month: Kolten Wong. The National League rookie crop is a dumpster fire. Wong only played 13 games in May, but hit .333/.418/.417, and that’s good enough to gain top honors this month. National League rookies are so bad this year. Of the top ten rookies (with at least 50 plate appearances) in OPS, nine are from the American League, and the tenth is Tommy Medica, a 26-year old bench player for the Padres. Also, there are only four NL rookie pitchers that have thrown at least 20 innings and have an ERA under 3.00 – a trio of relievers (David Hale, Brian Schlitter, Jeurys Familia), and Jacob deGrom of the Mets, who has made four starts.